You basically can trigger animations you own for your character when you're in a lobby or at the start of a game, by typing specific text.
Those animations, or "motions" rather, can be bought (as far as I know), at the store for beats.

Also if you see I'm missing anything, make sure to rage on the comments below, ty.

This time, this full guide is 80%/100% me, and maybe 20% the comments, if someone -does- end up saying anything I'm missing.